Safe to flush and replace filter on a high mileage X5 4.4i?

[Johnny_5]

Ive been pondering on this for a while where I want to replace the transmission fluid and filters but getting mixed info regarding safe or not safe for higher mileage X5's. Heard it can cause the transmission to fail and causes more issues than good. Currently at 200k and I have no records of this ever being done. Any insight or thoughts would be great!

[ezrax5]

I would like to know as well. I have 134,000

[x5Alpine]

I say do it. fresh fluid at small increments will be fine. I did it twice on my 4.6is 120k and 140k and the transmission shifted perfectly. It was original as well.

[mike_dmt]

For sure. I did it and am pleased. Take a close look at the connections on the wiring harness. (Inside)

If they are super brittle, it will give you headaches later if they break or wont stay connected, it causes all sorts of shifting issues.

Also make sure to get the good pan gasket. A plain cork one will likely fail prematurely. It's worth the extra $15

[David.X5]

I would be careful of the "flush" step. In a garage, they pump generic atf through the transmission. I've never found a place that does this with the $20-$40/liter synthetic fluid specified by BMW.

I did drain, drop pan to change filter, cleaned pan and refilled with Pentosin ATF1 at 135k miles. Repeat if you want to change a higher percentage of the fluid. About 2-3 liters is retained each time. Mines been going strong for another 10k miles since. Definitely seemed a little low at the time.

[tmv]

Drain and refill with filter change. Do not flush the transmission. That would do more harm than good.

[upallnight]

Originally Posted by David.X5

I would be careful of the "flush" step. In a garage, they pump generic atf through the transmission. I've never found a place that does this with the $20-$40/liter synthetic fluid specified by BMW.

I did drain, drop pan to change filter, cleaned pan and refilled with Pentosin ATF1 at 135k miles. Repeat if you want to change a higher percentage of the fluid. About 2-3 liters is retained each time. Mines been going strong for another 10k miles since. Definitely seemed a little low at the time.

Perhaps that's why the trans goes after flush at one of those trans shop that perform the flush.

[David.X5]

Its a funny question to ask (what fluid they use) - I've always gotten a deer in headlights look. I had various shops proposed to do this on different cars over the years that mostly required expensive synthetic ATF. Those "power flush" machines use something like 20 liters of fluid - no way they can use anything even remotely close to the spec fluid and still do it for $100 or $200. At $1000 it would be conceivable, but probably cause some customer gripping...and then I still wouldn't trust them not to substitute the generic fluid and pocket the change. But I have a !$%&! cynical streak.